TITLE:
Leaf Gas Exchange, Photon Capture and Light Harvest in Aldina heterophylla along a Vegetation Gradient in the Amazon Rainforest
AUTHORS:
João Victor Figueiredo Cardoso Rodrigues, José Francisco de Carvalho Gonçalves
KEYWORDS:
Chloroplast Pigments, Dark Respiration, Net Photosynthesis, Physiological Plasticity, Tropical Forest, Biomass Accumulation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.10,
May
12,
2014
ABSTRACT: Adaptation along
environmental gradients is presumed to induce physiological and biochemical
leaf changes in plant species. In this paper, we report how leaf gas exchange,
photon capture and light harvest for photosynthesis in Aldina heterophylla change along a vegetation gradient from low
stature open vegetation on extremely nutrient-poor white sand (Campina, CP),
through inter-mediate closet type (Campinarana, CR) to tall closed rain forest
(RF). The pigment concentrations did not differ between the CP, CR and RF
habitats. The performance index for the photosynthesis (PIABS) of individuals
in RF and CP was approximately 30% higher than that in CR individuals. This
species showed similar potential rates of photosynthesis in the different
vegetation types; however, the dark respiration rates were higher in CP. Our
results indicate that the differences in the leaves and soil nitrogen
concentrations are not enough to change the levels of gas exchange. Other
environmental features may be driving the observed morphological features in
this gradient, in particular, the tree height.